Copy Number Variants

The number of repeat on Genomic DNA fragment #1 is 22 and on Genomic DNA fragment #2 is 26.

DNA molecules were unique to an individual with the exception of monozygotic twins. Due to

Over the last 10 years scientists have been involved in the progression and completion of the Human Genome Project. "Scientists working on this project have developed detailed maps that identify the

In 1993 it was discovered that a segment of DNA on the arm of chromosome 4 is linked to the HD gene. They found that at one end of the HD gene, the combination CAG is repeated too many times. In people without HD this CAG is repeated 5 to 35 times. In people who are affected by HD, CAG is repeated over and over again between 36 and 121 times.

Imagine DNA as a ladder made of rungs — 3 billion in all — spiraling upward in a double helix. Each step is a base pair, designated by two letters from the nucleotide alphabet of G, T, A, and C. More than 99 percent of these base pairs are identical in all humans, with only about one in a thousand SNPs diverging to make us distinct. For instance, you might have a CG that makes you susceptible to diabetes, and I might have a CC, which makes it far less likely I will get this disease.

CHARGE syndrome is a genetic condition believed to be the result of a sporadic heterozygous mutation in the CHD7 gene. Experiments to determine the precise mutations within the CHD7 gene have concluded that mutations are scattered throughout the gene and include nonsense, frameshift and missense mutations as well as intragenic deletions (Martínez-Quintana et al., 2014). Intragenic deletions were initially reported in 2004 by a team who optimized array comparative genome hybridization (CGH) for high-resolution genome-wide screening of copy-number variations. Array CGH has since become a valuable, genome-wide screening tool for the detection of chromosomal aberrations in the form of copy number imbalances. By utilizing array CGH in two individuals with CHARGE syndrome, the team was able to report a 2.3 Mb de novo overlapping microdeletion on chromosome 8q12 (Vissers et al., 2004).

Gene duplication and amplification is a process by which variation can be created and selected for. By understanding gene duplication and amplification, scientists can glean insight on medical conditions dealing with this genetic phenomenon. In this study, scientists use Acinetobacter baylyi to understand the effects of gene duplication and amplification and the position of the amplified

discoveries is information regarding chromosomal and genetic disorders. Both chromosomal and genetic ailments can have harmful effects on the body. Genetic diseases such as Bloom's Syndrome occur as a result of gene alterations. These gene mutations cause the chromosomes to become unstable, leading to chromosomal breaks, separations and structural repositioning (Freivogel 170). Chromosomal diseases like Charcot-Marie Tooth Disease are also caused by mutations, which are nearly irreversible (Krajewski 232).

How has knowing the structure of the human genome changed the understanding of genetic disorders?

In February 2001, Venter et al., reported on the “penultimate milestone” – the feat of mapping 95% of the euchromatic portion of the human genome (Venter et al., 2001). Multiple discoveries were made in the process of mapping the human genome: the number of genes (fewer than imagined); the percent difference between individuals (less than 0.1%); and new techniques (Polymerase Chain Reaction) (Venter et al., 2001; National Human Genome Research Institute, 2012).

The Alu sequences epitomize the largest family of repetitive elements found in humans with over 5000 copies found in each genome1. They are widely considered to be a strong source of genetic variation, even possibly being the

Human genetics can play a major role in determining ones physical condition. One slight change in a genetic sequence can cause a disorder that can be life threating to the organism. Most of the genetic disorders are caused by recessive allele. In most cases this recessive allele is undetectable due to the disorder not being presented in the physical appearance. Hypercholesterolemia is an example of a human disorder controlled by a single gene. This human disorder causes high levels of cholesterol in an individual due to the absence of the low-density lipoproteins.

The Human Genome Project (HGP), an international scientific research project, has educated the public tremendously on various topics concerning DNA and genetics. This study has been beneficial to communities alike. As stated, the HGP sought to identify all the genes in human DNA, determine the sequences of the three billion chemical base pairs that make up human DNA, store this information in databases, improve tools for data analysis, transfer related technologies to the private sector, and address the ethical, legal, and social issues that may arise from the project. In favor of achieving these goals, scientists studied the genetic makeup of several nonhuman organisms (Human Genome Management Information System, 2011).

DeSalle and Michael Yudell. Welcome To The Genome: A User’s Guide to Genetic Past, Present, and Future. Canada: John Wiley & Sons. Inc., 2005. Print.

A chromosomal disorder is caused by an abundance or reduction of genes on the chromosomes. This type of disorder may also be caused by structural changes within these chromosomes; this is known as an aneuploidy (Porth, 2015). The most common chromosomal disorder is Down syndrome of which there are three types: complete trisomy 21, translocation, and mosaicism (Porth, 2015). Since its first identification in 1866, researchers have become more knowledgeable about the etiology of Down syndrome. When one studies etiology, pathogenesis, and clinical manifestations of Down syndrome, he or she will begin to understand multiple chromosomal disorders.